I recently converted from Windows Mobile to iPhone and I needed to figure out a way to manage my mobile MP3 library. With Windows Mobile I used Powershell and accessed the file system on my Windows Mobile device as a USB flash drive. To manipulate playlists on the iPhone I tried a few applications such as Winamp and MediaMonkey but they would not let me apply the time & genre based logic that I needed. So I found iTunesLibraryEditor which allowed me to access and modify iTunes playlists by instantiating the iTunesLibraryEditor object as such: